Renesas ISL78268EVAL1Z

Overview

ISL78268EVAL1Z from Intersil is an automotive-grade evaluation board designed to demonstrate and validate the ISL78268 55V synchronous buck controller with integrated 3A driver, supporting input voltages from 5V to 55V, adjustable switching frequency (50kHz–1.1MHz), constant current regulation, and AEC-Q100 qualification for battery charging and power conversion in harsh environments.

For engineers reviewing the ISL78268EVAL1Z datasheet, ISL78268EVAL1Z user guide (AN1946), ISL78268EVAL1Z application schematics, or ISL78268EVAL1Z pinout configuration, this board enables rapid prototyping of high-efficiency, high-voltage DC/DC converters with diode emulation mode, adaptive dead-time control, and comprehensive fault protection including hiccup/latch-off selectable responses.

Technical Context

The ISL78268EVAL1Z implements a peak current mode PWM architecture with dedicated average output current modulation loop-enabling precise constant-current regulation for supercapacitor charging and temperature control systems. It supports dual current sensing (ISEN1P/N for peak, ISEN2P/N for average) and integrates a 5.2V LDO for PVCC/VCC biasing.

This evaluation platform validates the ISL78268's full feature set: 24-pin 4×4 QFN package with thermal EPAD, adaptive dead-time control on UG/LG outputs, external synchronization via FSYNC, and flexible soft-start via SS capacitor. The board accommodates both DCR- and resistor-based current sensing and supports forced PWM or diode emulation operation modes selected via IMON/DE pin configuration.

Key Specifications

Availability

ISL78268EVAL1Z is available at Aetrix Electronics and suitable for automotive power design validation, supercapacitor charging system development, and industrial DC/DC converter prototyping requiring stable component supply, traceable sourcing, and long-term lifecycle support.

Supply support for ISL78268EVAL1Z includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Intersil (now part of Renesas Electronics) is a semiconductor company specializing in high-performance analog and mixed-signal ICs for power management, precision analog, and interface applications.

The ISL78268 product line was engineered specifically for automotive-grade DC/DC conversion-delivering high-voltage resilience, precise constant-current regulation, and robust fault handling in engine control units, ADAS power supplies, and battery management subsystems.

FAQ

What is the primary function of the ISL78268EVAL1Z evaluation board?

The ISL78268EVAL1Z evaluation board is a fully assembled, tested platform designed to demonstrate and accelerate development using the ISL78268 55V synchronous buck controller. It implements a complete reference design-including gate drive circuitry, current sensing, feedback compensation, and protection logic-to validate performance under real-world conditions such as automotive battery charging and industrial power conversion. The ISL78268EVAL1Z enables immediate evaluation of the ISL78268's constant-current regulation, diode emulation mode, and fault response behaviors without custom PCB design.

Does the ISL78268EVAL1Z support both DCR and shunt-based current sensing?

Yes, the ISL78268EVAL1Z supports both DCR sensing and shunt resistor-based current sensing configurations. Its layout and component placement accommodate either method for ISEN2P/N inputs, enabling accurate average output current measurement required for constant-current applications like supercapacitor charging. The board's schematic (per AN1946 and FN8657 Figure 5) shows optional DCR network components (CDCRS, RDCRS), while standard shunt implementation uses discrete sense resistors (RSEN2). This flexibility allows designers to optimize for accuracy, cost, or thermal performance based on their specific ISL78268EVAL1Z use case.

How is switching frequency configured on the ISL78268EVAL1Z?

Switching frequency on the ISL78268EVAL1Z is configured either by selecting a resistor value on the FSYNC pin (RFSYNC) or by applying an external clock signal to that same pin. With RFSYNC = 40.2kΩ, the nominal frequency is 300kHz; values of 249kΩ and 10kΩ yield ~50kHz and ~1.1MHz respectively. The board also supports synchronization across multiple ISL78268 controllers via CLKOUT-to-FSYNC daisy-chaining, enabling interleaved operation for reduced input/output ripple. All frequency settings are validated per the ISL78268EVAL1Z User Guide (AN1946) and electrical specifications in FN8657 Rev 3.00.

What protection features can be evaluated using the ISL78268EVAL1Z?

The ISL78268EVAL1Z enables hands-on evaluation of all key ISL78268 protection mechanisms: cycle-by-cycle peak current limiting (via ISEN1P/N), average overcurrent protection (via IMON/DE threshold detection), input and output overvoltage protection (VIN_OV, Vo_OV), overtemperature shutdown (OTP), and configurable fault response (hiccup vs. latch-off selected via HIC/LATCH pin). These protections are implemented in hardware on the board with accessible test points and jumper options, allowing engineers to trigger and observe fault behavior-including PGOOD assertion, soft-start restart timing, and recovery sequences-as defined in the ISL78268EVAL1Z User Guide and FN8657 datasheet.

Is the ISL78268EVAL1Z compatible with AEC-Q100 Grade 1 requirements?

Yes-the ISL78268EVAL1Z is built around the ISL78268, which is explicitly qualified to AEC-Q100 Grade 1 (−40°C to +125°C ambient operating range) and designed for automotive applications. The evaluation board itself uses automotive-grade passive components, thermal management features (including exposed pad grounding per QFN layout guidelines), and conforms to recommended PCB practices outlined in FN8657 for high-reliability operation. While the board is not itself certified, it provides a validated platform to assess ISL78268 compliance in end-system environments meeting Grade 1 thermal, vibration, and EMI requirements-making the ISL78268EVAL1Z essential for pre-compliance validation in automotive power designs.